After three years of doctors misdiagnosing her two sons, Kim Panton of Duxbury learned that her boys had PANDAS – Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus.

Treatment for the disorder is not covered by Panton’s health insurer, and the cost is steep: A single intravenous treatment can range from $7,000 to $15,000, according to Dr. Jolan Walter, director of the Pediatric Immunodeficiency Program at MassGeneral Hospital for Children.

The disorder’s symptoms may include characteristics of obsessive-compulsive disorder and vocal and motor tics that can be caused by a reaction in the brain triggered by strep bacteria.

The expensive treatment is weighed as an option when patients exhibit severe symptoms or have tried other treatment options without success.

A bill before the Legislature’s Joint Committee on Financial Services would require insurance companies to pay for the treatment, called intravenous immunoglobulin (IVIG) therapy.

State Rep. Josh Cutler, D-Duxbury, signed on as a co-sponsor of the bill after local families brought the little-known disorder to his attention. He said their plight struck a chord with him because he has a young son himself.

“We want doctors and families to be able to make the best medical decisions they can for these kids without having to worry if their insurance company might decide to arbitrarily deny coverage,” Cutler said.

The cure for PANDAS and the condition itself are controversial. Research on both has been limited.

Dr. Kyle Williams, director of the Pediatric Neuropsychiatry and Immunology Clinic at Massachusetts General Hospital, said no test can guarantee a diagnosis of PANDAS.

He also noted that two completed research studies at the National Institutes of Health involved fewer than 20 children.

“We do not have a great deal of evidence,” Williams said. “Both sides have an argument.”

Harvard Pilgrim did not respond to several attempts to seek comments about the disorder.

Kathleen Makela, a spokeswoman for Blue Cross Blue Shield of Massachusetts, said she could not immediately answer questions.

Williams testified for the legislation before the joint committee March 5. His group at MGH continues to test the efficacy of the IVIG treatment. Based on the price and risk of the medicine, he said his group discourages initial and multiple doses of the intravenous treatment before considering other treatment options.